June/July 2008

Rockin' and rollin' on the West Coast

Delivering construction aggregates to eager customers on the western seaboard

By
M. Westerlund

Loaded barge on the way to Vancouver

California is experiencing some growing pains. Various factors such as population growth, large-scale infrastructure projects and earthquake reinforcement programs make it the second-largest consumer of construction aggregates in the United States (Texas is the largest). However, sharp declines in locally available aggregates and intense opposition to the permitting of new quarries near major urban markets have translated into increasing shortages of these critical construction materials.

In an effort to satisfy this growing demand, Polaris Minerals Corporation, which owns a majority interest in the Orca Quarry, a large sand-and-gravel operation near Port McNeill on the northern portion of Vancouver Island, faced a big challenge: how to transport its low-value product to distant customers in an economically viable manner.

Polaris, a publicly traded Canadian company, solved this problem by mastering the efficient production and movement of large volumes of sand and gravel. The company’s complicated but efficient logistical chain combines a modern quarry operation with self-unloading bulk carriers, to expertly deliver construction aggregates to a growing roster of customers in cities on the western seaboard of North America, including Vancouver, San Francisco and Honolulu.

The Orca Quarry

The Orca Quarry is owned 88 per cent by Polaris and 12 per cent by the Namgis First Nation. It hosts a reserve of 134 million tons of high-quality sand and gravel — only 12 per cent of the deposit is oversized and requires crushing. The quarry is permitted to produce 6.6 million tons annually and is located 1.6 kilometres from a deep and navigable waterway. Polaris began operations in February 2007 and produced 1.4 million tons that year. The company estimates that the quarry will ship increasingly larger amounts in the coming years as the quarry approaches its permitted production level.

“These materials are traditionally trucked to customers; however, we are able to compete effectively through the efficient utilization of bulk ocean-going carriers,” said Herb Wilson, COO of Polaris Minerals Corporation. “We have become a logistics company and a quarrying company.”

Wilson said while the devil is in the details, when it comes to moving aggregate products to customers in coastal North American cities, the results speak for themselves. “During my 35 years in the quarrying business I have never witnessed such a fast and smooth ramp-up as we are achieving at the Orca Quarry,” said Wilson, adding that the team at the quarry deserves much of the credit.

Operations

Operations at the Orca Quarry begin with the efficient extraction of raw material. Rather than use a traditional loader and haul-truck combination, three Caterpillar 637G scrapers are used for both primary loading and hauling. This is a rare application for these machines, but it’s the most efficient method of harvesting the loosely consolidated, boulder-free material. The scrapers add operational benefits by blending the material as they harvest along the active face of the deposit.

The quarry’s state-of-the-art processing plant was designed on a turnkey basis by Metso Minerals. During the entire plant process, the material travels by conveyor, eliminating the need for trucks or loaders to transfer the material between processing stages.

Each of the four finished product stockpiles — two for sand, one each for coarse and fine gravel — have about 150,000 tons gross and 50,000 tons live capacity. This ensures sufficient inventory for rapid ship or barge loading. Sand and gravel from the stockpiles is conveyed to bulk carriers by a 5,000-ton-per-hour conveyor and shiploader system. The quadrant-beam shiploader is able to load an 80,000-ton bulk carrier in less than 24 hours. In fact, the quarry set a record for CSL International, the operator of the world’s largest fleet of rapid self-unloading freighters, when it loaded one of its ships in just 17 hours.